Percussion device.



G. H. ROWE. PERCUSSION DEVICE.

APPLICATION FILED MAY 16, 1910.

1,024,025; Patented Apr. 23, 1912.

3 SHEETS-SHEET 1.

v I 13 i7 40 G. H. ROWE.

PERCUSSION DEVICE.

APPLICATION FILED MAY 16, 1910.

1,024,025. Patented Apr. 23, 1912.

3 BHEETSSHEET 2.

i \X \k 3 7 16 COLUMBIA PLANOGRAPH 60., WASlllNGTON. D. C.

v G. H. ROWE. PERCUSSION DEVICE.

APPLICATION FILED MAY 16, 1910.

1,024,025. Patented Apr. 23, 1912.

3 BHEETSSHBET 3.

Im 91ml Wll WE Ev UNITED STATES PATENT OFFICE.

GEORGE H. ROWE, OF BERWYN, ILLINOIS, ASSIGNOR TO ELECTED-MAGNETIC TOOL COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

PERCUSSION DEVICE.

Specification of Letters Patent.

Patented Apr. 23, 1912.

Application filed May 16, 1910. Serial No. 561,696.

To all whom. it may concern:

Be it known that I, GEORGE H. ROWE, acitizen of the United States, residing at Berwyn, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Percussion Devices, of which the following is a specification.

My invention relates to a percussion de vice; and one of the primary objects of the invention is to provide a device of this character in which the striking element has rotary movement and in which the connection of the striking element with its driving means is of such character as to' allow the striking element to yield after the blow has been delivered so that it can be moved out of the way of the object struck, in readiness to deliver another blow. The invention contemplates particularly utilizing the force of magnetic attraction for making such connection between the striking element and its driving means.

A further object of the invention is to provide a percussion device of the type utilizing a magnetic connection between the striking element and its driving means, which, instead of employing a reciprocating electromagnet or magnetized member, such as heretofore has been used, employs a rotating magnet whereby a very greatly increased number of blows per unit of time is obtainable, with the advantage also of a lighter and simpler construction.

The invention has for further objects the several other new and improved constructions, arrangements and devices in percussion apparatus which will be hereinafter described and claimed.

The invention is illustrated in several embodiments in the accompanying drawings, wherein Figure 1 is a plan view of one form of device. Fig. 2 a fragmentary sectional view taken on line 22 of Fig. 1, looking in the direction of the arrows. Fig. 3 a sectional view on line 33 of Fig. 2, looking in the direction of the arrows. Fig. 1 a

fragmentary sectional View on line 4.4 of Fig. 1, looking in the direction of the arrows. Fig. 5 a perspective view of a preferred form of striking element. Fig. 6 a diagrammatic view of a form of apparatus modified with respect to the wiring. Fig. 7

a side view of a different type of percussion device constructed on the rotary principle.

at one end, preferably, with the handle 18 and closed at the other end by a head 19 in which is arranged a ball bearing 20, of

familiar construction, for the shaft 21 of the armature 15. The other end of this shaft is mounted in a bearing 22 on a bracket 23, shown as formed integrally with the head 19; the bracket being preferably constructed with a handle 24. Rigid on the ar- .mature shaft 21 are the two disks 25, be-

tween which is pivoted the striking element 26 having preferably, the wedge-shaped hammer portion 27 and the hub part 28, which latter lies between the bosses 29 on the disks 25, a pivot pin 30 extending through hub 28 and bosses 29. Secured to the disks, outwardly of the bosses 29, are the laminated cores 31 of the electro-magnets 32, the cores 31 terminating in the pole pieces 33, having inclined faces corresponding to the inclined faces of the striking part 27 The cores are shown as bolted to disks 25 by the bolts 34 and nuts 35. The impact receiving element is shown in this embodiment of the invention as a tool carrier 36, adapted to hold a drill 37; the tool carrier being provided with a shank 38 which extends through a nipple 39 in a boss 40 on a bracket 41, preferably formed integrally with head 19. In these figures I have indicated a wiring which will enable the device to be operated by a direct current. The magnets 32, in this case, are supplied from the armature by wires 42 which are shown as extending through armature shaft 21, which is hollow. It will be understood that these wires are so connected at two points in the armature winding that, when the motor is supplied with direct current, the current in the magnets will be at its maximum at the moment that the striking part 27 delivers its blow against the shank 38 of the tool carrier. For example, in the drum wound armature shown in the drawings the wires 42 are connected to the winding or element of the armature which stands at ninety degrees from the brushes when the hammer 27 delivers its blow. The same arrangement can be used in connection with an alternating current synchronous motor.

The operation of the device, as above described, is as follows: Nhen the motor and the magnets 32 are supplied with current the disks 25 will be revolved and with them the striking part which will be held between the pole pieces 33 of the magnets by magnetic attraction. Preferably, although not necessarily, as I apprehend it, the striking part should be made wedgeshaped, as shown, and the pole pieces correspondingly formed so that there is an iron to iron con tact between these parts, and in order that the striking part may be accurately held in the proper position to deliver a straight blow against the shank 38 of the tool carrier. The mode of operation of the device will depend to a certain extent upon the proportion of the parts, the weight of the striking element, the strength of the field produced by the magnets and the speed at which the motor is run. With the motor running at a high rate of speed and with magnets 32 which are relatively weak, the striking part will be forced out of the sphere of attraction of the magnets when the blow is struck, and will, therefore, drop back and so clear the end of shank 38. In this case, centrifugal force will bring the striking member into or approximately into position to strike the next blow. But it has been found in apparatus of somewhat similar character, in which centrifugal force alone was relied upon, that in practice it was very difficult under some circumstances to bring the striking part into a position perpendicular to the axis of the object which receives the impact at the moment the impact occured, the position of the striking part being usually a trifle oblique, and that as a result of this a glancing blow was delivered, which soon destroyed the mounting of the part designed to receive the impacts. My use of magnetic attraction overcomes this difficulty because after the striking part has been brought by centrifugal force into the field of the magnets, the force of magnetic attraction completed the proper positioning of such striking part. Moreover, the employment of magnetic attraction obviously increases the force of the impacts in proportion to the strength of such magnetic attrac tion. The use of magnetic attraction may, however, in some cases be dispensed with.

It is possible to design the machine, having regard to the weight of the striking part, its radius relative to the radius of the disks and the strength of the magnets, so that the striking part will not leave the sphere of attraction of the magnets. In this case, if the motor be operated at a high speed, the rebound of the hammer against the attractive force of the magnets will enable the striking part to clear the shank of the tool holder. Of course, with this operation of the device, centrifugal force plays some part, although relatively inconspicuous, in returning the striking element to its striking position. The iron to iron contact between the striking part and the pole pieces increases the force of the impact by eliminating air gaps from the magnetic circuit and utilizing surface adhesion.

It will be seen that the disks 25 form a momentum wheel to steady the operation of the apparatus.

In a device constructed as above described, it is possible to operate at fifteen hundred revolutions per minute and probably at much higher speeds.

The hammer 27 is thrust into the wedge shaped opening between the inclined surfaces of the parts 33. This limits the forward stroke of the hammer and insures a direct blow on shank 38. That is, the hammer is brought into substantial perpendicular relation to the impact receiving element at the moment of impact. The parts 33 constitute, therefore, an abutment or stop for the hammer at the end of its forward stroke.

In Fig. 6 I have shown an arrangementwhich is similar to that above described, except that the magnets and motor are independently supplied. 43 designates the com mutator of the armature supposing the mo tor to be a direct current, 44 the supply circuit, 45 the brushes, 46 conductors leading from the supply circuit to the brushes 4-7 which bear against collector rings 48, with which the wires 49, leading to the magnets 32, are connected. My invention, however, is not limited to any particular method of connecting up the magnets with the motor. The motor may be either shunt or series.

In Fig. 9 I have shown a device con structed on the same general principles as that shown in Figs. 1 to 5 inclusive, but which is different in its mechanical form. On the end of shaft 50 of the motor armature 51 is a bevel gear 52 which meshes with a bevel gear 53 on a shaft 54, mounted in bearings 55. The shaft 54 carries the disks 56 provided with the magnets 57, the striking part 58 being pivoted between the disks with its hammer portion adapted to extend between the magnets 57, just as these parts are arranged in the form of device already described. The casing 59 of the machine terminates in a nose-piece 60, carrying a nipple 61 through which extends the shank of the rivet set 62, in position to be struck by the striking element 58. Preferably, the casing of the apparatus will be provided with a handle 63.

The form of device last above described, I consider as mechanically preferable to that shown in the first five figures. My invention, broadly speaking, is not limited to any particular mechanical construction.

In Figs. 7 and 8 I have shown a rotary magnetic percussion device which, instead ofntilizing the direct pull of a magnet, is constructed in accordance with the principle of the induction motor. 'The field member of this device consists of a coil 64: arranged on a shaft 65 which is adapted to be driven by any suitable form of driving device (not show Secured to shaft 65 at each side of the coil 64 is a ring 66 provided with sectoral projections 67, formed with curved portions 68 which are at right angles to said sectoral portions and extend between the coil 64 and the cylindrical armature 69. It will be understood that the projections 67 on the ring at one side of coil 64 are in staggered relation with the projections on the ring at the other side of the coil. The armature 69 is formed with a series of bores in which are the copper rods 70. The ends of the rods 70 are secured in copper rings 71 on each end of the cylinder 69, which, it will be understood, is ordinarily made of soft iron. The striking part 72 is pivoted to a projecting shoulder 73 on the armature 69. A light fiat spring 74 is secured to shoulder 73 and bears against a screw 75, or other abutment on the striking part 72. This spring tends to keep the striking part close to the cylinder 69. lVith the cylinder revolving at a high speed the centrifugal force is, however,

.' sufficient to move the striking part into position to strike against the part 77, which may be the shank of a tool or any other device. The impact of the striking member 72 against the part 77 arrests the rotation of cylinder 69 and consequently the striking part drops or is forced by its spring out of the way of the part 77. The rotation of the cylinder 69 results from the currents induced in the squirrel cage construction consisting,

of the copper rods 70 and the rings 71, when the coil 6st and its pole pieces 66, 67 and 68 are rotated the operation being analogous to that of the induction motor. The shaft 65 is constructed with the contact rings 76 for the brushes 77 connected with the supply circuit 78; the rings 76 being connected with the ends of coil 64 by connections which are not shown.

As modifications in form, construction and arrangement of parts will readily suggest themselves to those skilled in this art, I do not limit myself to the particulars shown and described herein, except as the same are made limitations upon certain of the claims.

I claim:

1. In apparatus of the character described, the combination with a striking element, of driving means for the same comprising a rotating device, and means for producing a magnetic connection between said rotating device and said striking element.

2. In apparatus of the character described, the combination with a striking element, of driving means for the same comprising a rotating device to which said striking element is pivoted, and means for producing a magnetic connection between said rotating device and said striking element.

3. In apparatus of the character described, the combination with a striking element,'of driving means for the same comprising a rotating device constituting an inertia wheel, and means for producing a magnetic connection between said rotating device and said striking element.

4. In apparatus of the character described, the combination with an impact receiving element, of a striking element, driving means for said striking element comprising a rotating device with which said striking element is pivoted so that centrifugal force tends to move said striking element into position at right angles to said impact receiving element, and means for producing a magnetic connect-ion between said rotating device and said striking element for the purpose described.

5. In apparatus of the character described, the combination with an impact receiving element, of a rotating striking element com prising a pivotally'mounted member, which centrifugal force tends to bring into position at right angles with said impact receiving element, driving means, and means for producing a magnetic connection between said driving means and said striking element.

6. In apparatus of the character described, the combination with a rotating device, of a striking element connected with the rotating device so as to rotate therewith and a magnet which'eXerts an attractive force on said striking element tending to hold the same in a given relation with said rotating device.

7. In apparatus of the character described, the combination with a rotating device, of a striking element connected with the rotating device so as to rotate therewith, and a magnet on said rotating device which exerts device, and a magnet which exerts an attractive force upon said striking element tending to hold the same in a given relation with respect to said rotating device.

9. In apparatus of the character described, the combination with a rotating device, of a striking element pivoted at one end to said rotating device, and a magnet positioned so as to exert an attractive force against the other end of said striking element, tending to hold the same in a given relation to said rotating device.

10. In apparatus of the character described, the combination with a rotating device, of a striking element eccentrically pivoted thereto, and means for exerting a magnetic attraction on said striking element which tends to keep the same in a given relation with respect to said rotating device.

11. In apparatus of the character described, the combination with a rotating device, of a striking device pivoted to said rotating device, and a magnet on said rotating device which attracts said striking element and at the same time provides a stop for the same.

12. In apparatus of the character described, the combination with a rotating device, of a striking element pivoted to said rotating device, and a magnet on said rotating device which attracts said striking element and at the same time provides a stop for the same, said magnet and striking element having engaging wedging surfaces.

13. In apparatus of the character described, the combination with a rotating device, of a striking element pivoted thereto and a magnet on said rotating device with which said striking element is in contact when in striking position.

14:. In apparatus of the character described, the combination with a rotating de' vice, of a striking element pivoted thereto and a pair of magnets on said rotating device, one on each side of said striking element with which said striking part is in contact when delivering its blow.

15. In apparatus of the character described, the combination with a rotating device, of a striking element pivoted thereto and a pair of magnets on said rotating device, one on each side of said striking element with which said striking part is in contact when delivering its blow, said striking part being wedge-shape and said magnets being similarly conformed substantially as described.

16. In apparatus of the character described, the combination with a pair of disks which rotate together, a striking part pivoted between said disks and magnets on said disks which exert an attractive force upon said striking part.

17. The combination with a rotating device, of a striking element pivoted thereto and having a wedgeshaped portion, and means on said rotating device providing a wedgeshaped opening into which thewedge-shaped portion of the striking element is received and positioned to deliver its blow.

18. In apparatus of the character described, the combination with a rotating device, of a striking element pivoted thereto, means comprising an electro-magnet for producing a magnetic connection between the striking element and the rotating device, and an electric motor to drive the rotating device in unison with its armature, the winding of the armature being electrically connected with the windings of said magnet so that the current in the magnet is at a maximum when the striking element delivers its blow.

19. In apparatus of the character described, the combination with a rotating device provided with converging walls constituting a stop, of a striking element pivoted to said rotating device and mounted to be swung into said stop and thereby automatically positioned for delivering the blow.

20. In apparatus of the character described, the combination with'a rotating device of a striking element pivoted thereto and means on said rotating device constituting a stop to limit the forward movement of the striking element and to position the same for delivering a blow, said stop being formed with converging surfaces oblique to the plane of oscillation of the striking ele ment.

21. In apparatus of the character described, the combination with a rotating device of a striking element pivoted thereto and having a wedge-shaped portion, of means on the rotating device providing a stop having converging surfaces to receive the wedge-shaped portion of the striking element so as to position said striking element laterally and limit the movement thereof forwardly.

22. In apparatus of the character described, the combination with a rotating device of a striking element carried thereby, means comprising an electro-magnet for producing a magnetic connection between the striking element and the rotating device, and an electric motor to drive the rotating device, the winding of the armature of said motor being electrically connected with the winding of said magnet.

23. In apparatus of the character described, the combination with an electric motor of a rotating device which is rigidly connected with the armature of the motor, a striking element pivoted to the rotating device, and means comprising an electromagnet for producing a magnetic connection between the striking element and the rotating device; the winding of said armature being electrically connected with the 10 winding of said magnet so that the current in the magnet is at a maximum when the striking element delivers its blow.

GEORGE H. ROWE.

Witnesses:

P. H. TRUMAN, H. L. PECK.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

